The invention relates to a blockage detector for detecting a blocked state of an electrical machine. The electrical machine may be a rotating field machine or a linear machine. In particular, the electrical machine may be a brushless DC motor.
The invention also relates to an inverter controller having a blockage detector.
In addition, the invention relates to an inverter having an inverter controller which has a blockage detector.
Furthermore, the invention relates to a brushless DC motor having such an inverter and to a drive, ventilation or air-conditioning system having such a brushless DC motor. The invention also relates to a vehicle having such a drive, ventilation or air-conditioning system.
The invention also relates to a method for detecting a blocked state of an electrical machine.
DE 10 2010 049 169 A1 describes a monitoring computer for calculating a monitoring speed of a brushless DC machine by means of a field-oriented machine model without a speed sensor. If a discrepancy between the monitoring speed and a rotary transducer signal is outside a tolerance range, an operating fault (for example on account of a sensor error) is inferred. In order to also be able to record the monitoring speed in an operating range around zero hertz using the sensorless method, it is proposed to apply test signals to the stator windings. Providing the test signals is associated with an additional amount of effort.